This recent pilot study, conducted on the GCRC, suggested that soy protein isolate (SPI) may be effective in treating several manifestations of Hereditary Hemorrhagic Telangiectasia (HHT) including migraines, epistaxis and GI bleeding. Soy was utilized because a component of soy (genistein) has been recently found to inhibit angiogenesis and HHT has been suggested to be a defect of excessive endothelial proliferation. Based on the results of the pilot study, a grant from the Illinois Soybean Board has enabled us to perform two larger placebo, controlled, crossover trials of SPI for the treatment of chronic epistaxis and migraines in HHT.